Endotracheal intubation is a common technique that is used when an individual (hereafter referred to as the patient) must be ventilated such as after receiving a general anesthetic. The technique consists of placing an endotracheal tube (i.e. a flexible, plastic tube) into the patient's trachea to ventilate his/her lungs. During intubation, the endotracheal tube must be inserted past the patient's teeth and tongue and then past the epiglottis and the vocal cords into the trachea. The endotracheal tube should be placed about 1 to 2 inches before the bifurcation of the trachea in order to ventilate both of the patient's lungs equally.
An anestheologist, ER physician, RT, paramedic or any other suitable medical practitioner, passes the endotracheal tube into the trachea with the aid of a laryngoscope that is introduced into the patient's mouth and upper airway. The laryngoscope consists of a blade of varying size, a fiberoptic light source and a handle that contains the power source for the light. The blade of the laryngoscope, which is curved for adults, is used to move the patient's epiglottis to expose the underlying glottis (the epiglottis and glottis form a valve-like structure which provides an opening to the trachea). An opening is then formed through which two white vocal cords are seen. The tip of the endotracheal tube is then advanced through the vocal cords. At this point, the endotracheal tube is secured and a pressure cuff, on the outside of the endotracheal tube, is inflated so that the endotracheal tube pushes against the inner lining of the trachea. This is done to provide a clear airway for the patient and to prevent the aspiration of blood, mucus and gastric acid which is important since these materials may cause pneumonitis or bronchial obstruction. The endotracheal tube is then secured such that it is held tightly in place and not allowed to slide up and down the patient's trachea.
In certain cases, the epiglottis and glottis valve-like structure, as well as the vocal cords, form what is known as a “difficult airway”. This difficult airway presents a challenge to the medical practitioner who is performing the intubation. The difficult airway is particularly troublesome in the case of blind intubation, in which the vocal cords are not directly visible with a conventional laryngoscope. This problem may be compounded by patients who have, for example, a short muscular neck with a full set of teeth, a receding lower jaw or temporo-mandibular disease. As a result it is likely that the intubation process will fail. Since 1992, failed intubations have resulted in one third of all anesthesia related deaths during operation procedures. In addition, failed intubation may also lead to bleeding, swelling, laryngospasm, discomfort and hoarseness. Therefore, professionals in the field of anesthesiology are interested in improving the intubation process.
In response, many devices have been developed that are used to gain “blind” access to the trachea. Currently, there is a surge of interest in flexible fiberoptics that are used, either alone or in conjunction with endotracheal tubes, to perform intubation. However, scopes employing flexible fiberoptics are costly and employ a display means, such as an eyepiece or a remote screen display, that is awkward to use during the intubation process. The high costs result in limited access to these devices which consequently leads to a lack of user skill for these types of scopes. This makes the use of these fiberoptic scopes both time consuming and cumbersome which is troublesome for situations in which the medical personnel must act quickly.